It's showing code 42

Tiny
JES 1
  • MEMBER
  • 1990 CHEVROLET S-10
  • 4.3L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 236,000 MILES
I have replaced distributor cap rotary button new plugs and wires new coil new map sensor new ignition module new alternator the truck runs great when cold on the highway can go 20-30 miles in city goes approximately three to five miles when it warms up the check engine light comes on or flashes it trues to dye or does dye acts like the timing has jumped off the timing is off or something in that matter but does started back if I hold the peddle to floor shut it off long enough to cool down will run great again until it warms up then the same process the water temp never gets close to the red stays about normal
Saturday, February 13th, 2016 AT 4:36 PM

9 Replies

Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,005 POSTS
IF THE TIMING HAD JUMPED, IT WOULD NOT RUN GREAT ON THE NEXT VOYAGE.

MR. COMPUTER IS SCREAMING AT YOU THAT IT HAS SENSED A PROBLEM.

YOUR RIG IS OBD 1, (PRE-1996)

MOST AUTO PARTS STORES WILL READ YOUR CODES FOR FREE, THAT IS, MOSTLY OBD 2 VEHICLES.

IN MY TOWN, "AUTOZONE" IS CAPABLE OF READING BOTH, AND AGAIN, IT'S FREE!

WRITE DOWN THE EXACT NUMBERS, NOT WHAT THE FELLER MIGHT OFFER AS THE SOLUTION (EVEN THOUGH HE MIGHT BE DEAD ON) CODES CAN BE INTERPRETED DIFFERENTLY-NOT KNOWING THE NUMBERS WON'T HELP US AT ALL

WE MAY BE ABLE TO OFFER SUGGESTIONS

OTHER OPTIONS ARE BUY A SCANNER (SOME ARE INEXPENSIVE) HAVE A SHOP PULL THE CODES ('ROUND HERE ABOUT $50 OR SO). "YOU TUBE" MIGHT SHOW YOU HOW TO EXTRACT THE CODES.

ONCE YOU HAVE 'EM, YOU WILL HAVE SOMETHING TO GO ON, INSTEAD OF JUST THROWING EXPENSIVE PARTS AT IT.

CHECKING VACUUM LINES/ ELECTRICAL CONNECTIONS/ FUEL PRESSURE ARE OTHER THINGS THAT THE COMPUTER DON'T "CHECK" BUT THEIR EFFECTS MIGHT AFFECT THINGS THAT THE COMPUTER DOES MONITOR.

JUST TRYING TO SHOW YOU THE EZier THINGS TO CHECK 1st, BEFORE YOU MIGHT GET IN DEEPER.

(THANK GOODNESS, MINE ARE OLDER AND HAVE CARBS!)

YOUR TURN

THE MEDIC
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
-2
Saturday, February 13th, 2016 AT 6:46 PM
Tiny
JES 1
  • MEMBER
  • 6 POSTS
OK could it be due to the distributor was loose while driving the distributor may move and send a wrong signal to computer so there for it causes the computer send false or wrong signal to coil or distributor
Was this
answer
helpful?
Yes
No
+1
Saturday, February 13th, 2016 AT 9:42 PM
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
If you left eth dist loose and never timed it of course it will do what you say and give a code 42. Time the damn thing and lock dist down
Was this
answer
helpful?
Yes
No
+1
Sunday, February 14th, 2016 AT 8:34 AM
Tiny
JES 1
  • MEMBER
  • 6 POSTS
Is there a trick to timing it I heard you have to unhook something to set timing after set reconnect what ever it is you need to disconnect before setting
Was this
answer
helpful?
Yes
No
Tuesday, February 16th, 2016 AT 7:54 PM
Tiny
JES 1
  • MEMBER
  • 6 POSTS
OK set timing disconnected positive side of the battery cable then haircut minutes later to reset computer checked at EMC flash 12 three consecutive times which is letting you know that is reading code and flash no other codes drove it approximately 12 miles shut it off check codes again still flash no codes hour later driver 6 miles check engine light flashing made it to my destination check codes again flash 34 42 and 43 looked up codes 34 is MAP sensor 42 is electronic spark and 43 of spark knock wondering if the fuel pump when it gets warm can create these problems because after sitting there approximately 5 minutes restarted and drove it back to 10 miles and did just fine no check engine light or nothing that leads me to think maybe the fuel pump is getting warm and therefore creating these problems just taking a shot in the dark have sunk a lot of money into this so far trying to fix this problem
Was this
answer
helpful?
Yes
No
-1
Wednesday, February 17th, 2016 AT 5:30 PM
Tiny
JES 1
  • MEMBER
  • 6 POSTS
OK set timing disconnected positive side of the battery cable then after five minutes later reconnect positive to restore computer checked at EMC flash 12 three consecutive times which is letting you know that is reading code and flash no other codes drove it approximately 12 miles shut it off check codes again still flash no codes hour later driver 6 miles check engine light flashing made it to my destination check codes again flash 34 42 and 43 looked up codes 34 is MAP sensor 42 is electronic spark and 43 of spark knock wondering if the fuel pump when it gets warm can create these problems because after sitting there approximately 5 minutes restarted and drove it back to 10 miles and did just fine no check engine light or nothing that leads me to think maybe the fuel pump is getting warm and therefore creating these problems just taking a shot in the dark have sunk a lot of money into this so far trying to fix this problem
Was this
answer
helpful?
Yes
No
Wednesday, February 17th, 2016 AT 6:51 PM
Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,005 POSTS
I THOUGHT "42" WAS AN IGNITION MODULE ISSUE

IS MOUNTED ON THE DISTRIBUTOR

THE MEDIC
Was this
answer
helpful?
Yes
No
Wednesday, February 17th, 2016 AT 6:55 PM
Tiny
JES 1
  • MEMBER
  • 6 POSTS
I have a 90 s10 4.3 it has the OBD-11 THE OLDER TYPE WHERE the check engine light flashing tells you the code like it flashes 12 three times to let you know that its in diagnostic mode and code 42 is electronic spark timing (est) circuit you can find all code it's GM 2 digit trouble codes
Was this
answer
helpful?
Yes
No
Wednesday, February 17th, 2016 AT 7:15 PM
Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,005 POSTS
ROGER!

OBD II WAS MADE MANDATORY IN 1996

YOU SURE?

LET'S REVIEW JUST A LITTLE

WHEN OBD I CAME OUT-IT WAS USUALLY CALLED "OBD", AS THERE WAS NO OBD II UNTIL LATER (SOME MFGers, STARTED A LITTLE EARLIER THAN THE MANDATORY 1996)

OBD I CODES ARE USUALLY 2 DIGIT

OBD II (ON A SCANNER) ARE P0123, PO135 (JUST THROWING STUPID #s)

NOTICE THESE ARE NUMERICALLY 3 DIGIT NUMBERS (WITHOUT THE "P")

RECKON YOU HAVE BEEN CHASING THE WRONG ISSUE?

SCROLL DOWN SOME IN THIS LINK AND YOU WILL SEE CHEVY OBD II CODES

http://www.icheckengine.com/2011/09/chevrolet-specific-codes.html

NOT TRYING TO BE SMART, JUST TRYING TO FIGURE OUT THE DEAL!

SOMETIMES PEOPLE POST THEIR VEHICLE INFO WRONG (DURING THE INITIAL QUESTION), BUT YOU JUST POSTED IT IS A '90 LAST POST

THE MEDIC
Was this
answer
helpful?
Yes
No
-2
Wednesday, February 17th, 2016 AT 7:37 PM

Please login or register to post a reply.

Related OBD1 Code 42 Content

VIEW MORE